Industrial fabric

Abstract

An industrial fabric is a web woven from warp yarns made of monofilaments and weft yarns made of monofilaments. The warp yarns are of a double-layer structure. One of warp yarn basic units comprises four sub-units, two sub-units being located on an upper layer, the other two sub-units being located on a lower layer. The warp yarns on the upper layer and the warp yarns on the lower layer are vertically overlapped, wherein at least two sub-units comprise two parallel narrow warp yarns. Upper warp yarns and lower warp yarns are identical in texture structure, or one surface is identical to the other surface after rotating by 180 degrees. The industrial fabric is stable in structure and good in overall consistency. The upper surface is good in flatness, the surface is free from defects, and the quality and intensity of the fabric are improved.

Claims

1. An industrial fabric which is a web woven from warp yarns made of monofilaments and weft yarns made of monofilaments, wherein, the structure or texture of the warp yarns are of a double-layer structure comprising an upper layer in which upper layer warp yarns interlace with the weft yarns, and a lower layer in which lower layer warp yarns interlace with the weft yarns, wherein the upper layer warp yarns do not intersect with the lower layer warp yarns; one of warp yarn basic units comprises four sub-units, wherein two sub-units are located on the upper layer, the other two sub-units are located on the lower layer, the warp yarns on the upper layer and the warp yarns on the lower layer are vertically overlapped, wherein at least two sub-units comprise two parallel narrow warp yarns; and wherein the warp yarns have flat cross-sections respectively; upper warp yarns and lower warp yarns are identical in texture structure, or one surface is identical to the other surface after being rotated by 180 degrees; and wherein the double-layer structure is that: one sub-unit of the upper warp yarns has two parallel narrow warp yarns and the other sub-unit also has two parallel narrow warp yarns; one sub-unit of the lower warp yarns has two parallel narrow warp yarns and the other sub-unit also has two parallel narrow warp yarns; the two parallel narrow warp yarns of the upper sub-unit and the two parallel narrow warp yarns of the lower sub-unit are vertically overlapped.

2. The industrial fabric of claim 1, wherein the web is of a web with ends.

3. The industrial fabric of claim 2, wherein the seam structure of the web with ends is a pin loop seam or a spiral loop seam.

4. The industrial fabric of claim 1, wherein the cross-section of the warp yarns is rectangular.

5. The industrial fabric of claim 1, wherein the cross-section of weft yarns is circular or rectangular, of which the diameters or thicknesses are the same or different to each other.

6. The industrial fabric of claim 1, wherein monofilaments are made of polymeric resins, the polymeric resins comprise one or more of polyester monofilaments, PPS monofilaments, PEEK, PCTA and nylon monofilaments.

7. An industrial fabric which is a web woven from warp yarns made of monofilaments and weft yarns made of monofilaments, wherein, the structure or texture of the warp yarns are of a double-layer structure comprising an upper layer in which upper layer warp yarns interlace with the weft yarns, and a lower layer in which lower layer warp yarns interlace with the weft yarns, wherein the upper layer warp yarns do not intersect with the lower layer warp yarns; one of warp yarn basic units comprises four sub-units, wherein two sub-units are located on the upper layer, the other two sub-units are located on the lower layer, the warp yarns on the upper layer and the warp yarns on the lower layer are vertically overlapped, wherein at least two sub-units comprise two parallel narrow warp yarns; and wherein the warp yarns have flat cross-sections respectively; upper warp yarns and lower warp yarns are identical in texture structure, or one surface is identical to the other surface after being rotated by 180 degrees; and wherein the double-layer structure is that: one sub-unit of the upper warp yarns has one wide warp yarn and the other sub-unit has two narrow warp yarns; one sub-unit of the lower warp yarns has two narrow warp yarns and the other sub-unit has one wide warp yarn; one wide warp yarn on the upper layer and two narrow warp yarns on the lower layer are vertically overlapped, the width of the wide warp yarn is 0.6-1.5 times the sum of the widths of the two narrow warp yarns; two narrow warp yarns on the upper layer and one wide warp yarn on the lower layer are vertically overlapped, the width of the wide warp yarn is 0.6-1.5 times the sum of the widths of the two narrow warp yarns.

8. The industrial fabric of claim 7, wherein the web is of a web with ends.

9. The industrial fabric of claim 8, wherein the seam structure of the web with ends is a pin loop seam or a spiral loop seam.

10. The industrial fabric of claim 7, wherein the cross-section of the warp yarns is rectangular.

11. The industrial fabric of claim 7, wherein the cross-section of weft yarns is circular or rectangular, of which the diameters or thicknesses are the same or different to each other.

12. The industrial fabric of claim 7, wherein monofilaments are made of polymeric resins, the polymeric resins comprise one or more of polyester monofilaments, PPS monofilaments, PEEK, PCTA and nylon monofilaments.

13. An industrial fabric which is a web woven from warp yarns made of monofilaments and weft yarns made of monofilaments, wherein, the structure or texture of the warp yarns are of a double-layer structure comprising an upper layer in which upper layer warp yarns interlace with the weft yarns, and a lower layer in which lower layer warp yarns interlace with the weft yarns, wherein the upper layer warp yarns do not intersect with the lower layer warp yarns; one of warn yarn basic units comprises four sub-units, wherein two sub-units are located on the upper layer, the other two sub-units are located on the lower layer, the warp yarns on the upper layer and the warp yarns on the lower layer are vertically overlapped, wherein at least two sub-units comprise two parallel narrow warp yarns; and wherein the warp yarns have flat cross-sections respectively; upper warp yarns and lower warp yarns are identical in texture structure, or one surface is identical to the other surface after being rotated by 180 degrees; and wherein the double-layer structure is that: one sub-unit of the upper warp yarns has one wide warp yarn and the other sub-unit has two narrow warp yarns; one sub-unit of the lower warp yarns has two narrow warp yarns and the other sub-unit has one wide warp yarn; one wide warp yarn on the upper layer and one wide warp yarn on the lower layer are vertically overlapped; two narrow warp yarns on the upper layer and two narrow warp yarns on the lower layer are vertically overlapped.

14. The industrial fabric of claim 13, wherein the web is of a web with ends.

15. The industrial fabric of claim 14, wherein the seam structure of the web with ends is a pin loop seam or a spiral loop seam.

16. The industrial fabric of claim 13, wherein the cross-section of the warp yarns is rectangular.

17. The industrial fabric of claim 13, wherein the cross-section of weft yarns is circular or rectangular, of which the diameters or thicknesses are the same or different to each other.

18. The industrial fabric of claim 13, wherein monofilaments are made of polymeric resins, the polymeric resins comprise one or more of polyester monofilaments, PPS monofilaments, PEEK, PCTA and nylon monofilaments.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic structural view of a first embodiment of the present application (a front of the web).

(2) FIG. 2 is a rear view of FIG. 1 (a back of the web).

(3) FIG. 3 is a cross-sectional view along the line A-A in FIG. 1.

(4) FIG. 4 is a cross-sectional view along the line B-B in FIG. 1.

(5) FIG. 5 is a schematic structural view at the seam of an embodiment 1.

(6) FIG. 6 is a rear view of FIG. 5.

(7) FIG. 7 is a cross-sectional view along the line C-C in FIG. 6.

(8) FIG. 8 is a schematic structural view of an embodiment 2 of the present application (front of the web).

(9) FIG. 9 is a rear view of FIG. 8 (a back of the web).

(10) FIG. 10 is a cross-sectional view along the line D-D in FIG. 8.

(11) FIG. 11 is a cross-sectional view along the line E-E in FIG. 8.

(12) FIG. 12 is a schematic structural view at the seam of the embodiment 2.

(13) FIG. 13 is a rear view of FIG. 12.

(14) FIG. 14 is a cross-sectional view along the line F-F in FIG. 13.

(15) In order to describe clearly, the same numbers or letter numbers are used for the same elements in the figures. The L and R with arrows in the figure represent the left and right sides of the fabric, respectively, only for the convenience of the reader to identify the corresponding relationship in the figures.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(16) The dryer web described in the present application is a double-layer structure with warp yarns texture, i.e., an upper layer in which upper layer warp yarns interlace with the weft yarns, and a lower layer in which lower layer warp yarns interlace with the weft yarns, and the upper layer warp yarns do not intersect with the lower layer warp yarns. The warp yarns in all warp yarn textures have noncircular or generally rectangular cross-sections. The cross-section of weft yarns can be circular or rectangular or any other shape. Weft yarns of different sizes can be applied to the present fabric at the same time.

(17) The dryer web fabric in the present application is made of monofilaments and woven according to the designed texture structure. In the design of dryer web fabrics, different synthetic polymer resin monofilaments are selected according to different paper machines, different paper types and the special needs of different users. Commonly used monofilaments include polyester monofilaments and PPS monofilaments, other materials include polymers such as PEEK, PCTA, nylon and the like. Two or more different types of monofilament can be selected for warp yarns, and two or more different types of monofilament can also be selected for weft yarns.

(18) The front and the back texture of the present application are exactly the same, or the front texture is identical to the back texture after being rotated by 180 degrees, so that both the front side and the back side can be used as the sticker surface.

Embodiment 1

(19) The double-layer structure is that one sub-unit of upper warp yarns has one wide warp yarn and the other sub-unit has two narrow warp yarns; one sub-unit of lower warp yarns has two narrow warp yarns and the other sub-unit has one wide warp yarn; one wide warp yarn on the upper layer and two narrow warp yarns on the lower layer are vertically overlapped, the width of the wide warp yarn is 0.6-1.5 times the sum of the widths of the two narrow warp yarns; two narrow warp yarns on the upper layer and one wide warp yarn on the lower layer are vertically overlapped, the width of the wide warp yarn is 0.6-1.5 times the sum of the widths of the two narrow warp yarns.

(20) That is, one sub-unit of upper warp yarns is a wide warp yarn 4t with a rectangular cross-section, the other sub-unit is two parallel narrow warp yarns 1t, 2t with a rectangular cross-section; one sub-unit of lower warp yarns is two parallel narrow warp yarns 5b, 6b with a rectangular cross-section, the other sub-unit is a wide warp yarn 3b with a rectangular cross-section. The four warp yarn sub-units are woven in accordance with the texture diagram in Table 2 to form dryer web fabrics and are alternately arranged in the entire web.

(21) FIG. 1 and FIG. 2 are 3D views of the front and back of the dryer web fabrics in Table 1. As shown in the 3D views, the sum of the widths of the two front narrow warp yarns 1t and 2t is substantially equal to the width of the back wide warp 3b; similarly, the width of the front wide warp 4t is approximately equal to the sum of the widths of the back warps 5b and 6b. For example, the cross-sectional dimensions of 1t, 2t are 0.36 mm0.53 mm (thicknesswidth), and the cross-sectional dimensions of 3b or 4t is 0.36 mm1.06 mm (thicknesswidth) respectively.

(22) It can also be seen from FIG. 1 and FIG. 2 that the front texture of the dryer web is exactly the same as the back texture of the dryer web after being rotated by 180 degrees. Compared with the traditional design with different back and front textures, the present application can effectively eliminate the stress difference caused by the difference of the front and back textures, improve the consistency of the web texture remarkably, and obtain the smoother and flatter surface of the web. The backs of the warp yarns 1t, 2t, and 4t in the white frame of FIG. 1 are the warp yarns 3b, 5b, and 6b in the white frame of FIG. 2; similarly, the weft yarns 2w and 4w can also be seen.

(23) TABLE-US-00001 TABLE 1 Texture diagram of the first embodiment 1t 2t 3b 4t 5b 6b 4w x x x 3w x x x 2w x x x 1w x x x Weft Yarns Yarn Diameter 4w Diameter: 0.40-0.70 mm 3w Diameter: 0.70-1.00 mm 2w Diameter: 0.40-0.70 mm 1w Diameter: 0.70-1.00 mm Warp Yarns 3b 4t 1t 2t Lower Upper 5b 6b Upper layer layer layer Lower layer Yarn Thickness (mm): Thickness (mm): Thickness (mm): Diameter 0.25-0.50 0.25-0.50 0.25-0.50 Width (mm): Width (mm): Width (mm): 0.40-0.80 0.80-1.60 0.40-0.80

(24) FIG. 3 is a cross-sectional view along the line A-A of the dryer web in FIG. 1. This 3D view shows only the texture structure of warp yarns 1t, 2t, 3b and weft yarns 1w, 2w, 3w, 4w. It can be clearly seen from the figure that the diameters of 1w and 3w are thicker and the diameters of 2w and 4w are smaller. The upper warp yarn sub-units 1t and 2t are oriented in three upward and one downward, that is, three of them are above the weft yarns 1w, 2w, 3w and the other is below the weft yarn 4w. The lower warp yarn sub-unit 3b are wide yarns, which are oriented in one downward, one upward and two downward, that is, one of them is below the weft yarn 1w, one of them is above the weft yarn 2w and the other two are below the weft yarns 3w, 4w. The aforementioned warp and weft yarns cycle back and forth to form a first group of warp and weft yarn texture structure.

(25) FIG. 4 is a cross-sectional view along the line B-B of the dryer web in FIG. 1. This 3D view shows only the texture structure between warp yarns 4t, 5b, 6b and weft yarns 1w, 2w, 3w, 4w. Similarly, it can be seen from the figure that the diameters of 1w and 3w are thicker and the diameters of 2w and 4w are smaller. The upper warp yarn sub-unit 4t are oriented in one upward, one downward and two upward, that is, one of them is above the weft yarn 1w, one of them is below the weft yarn 2w and the other two are above the weft yarns 3w, 4w; the lower warp yarn sub-units 5b and 6b are oriented in three downward and one upward, that is, three of them are below the weft yarns 1w, 2w and 3w and the other is above the weft yarn 4w. The aforementioned warp and weft yarns cycle back to form a second kind of warp and weft texture structure and form a complete weave texture together with the first group of texture structure, which penetrates all the web bodies of the dryer web.

(26) FIG. 5 shows the 3D front view of the dryer web seam. As shown in the figure, when the 4t in the warp yarns is return-plugged on the left side of the dryer web, leaving a sufficient length of warp yarns as seam loops for return-plugging and forming the seam loops (i.e. 4t-loops) at the left side of the dryer web end; similarly, when 1t and 2t in the warp yarns are return-plugged together, leaving a sufficient length of warp yarns for return-plugging and forming return-loops (i.e. 1t/2t-loops) at the right side of the dryer web end. When warp yarns 1t and 2t are return-plugged at the left side of the dryer web, they must be return-plugged in tight against the weft yarn 3w and form return-loops (i.e. 1t/2t-return) and leave empty spaces for the seam loops of the warp yarns 1t, 2t at the right side of the dryer web; similarly, when the warp yarn 4t at the right side of the dryer web is return-plugged, it must be return-plugged in tight against the weft yarn 1w and form return-loops (i.e. 4t-return) and leave empty spaces for the seam loops of the warp yarn 4t at the left side of the dryer web.

(27) FIG. 6 is a 3D rear view of the dryer web seam. As shown in the figure, the warp yarns 1t, 2t at the left side of the dryer web, which are abutted against the weft yarn 3w and into abutment with the warp yarn 3b; the warp yarn 4t forms a seam loop and comes into abutment with the warp yarns 5b, 6b; the warp yarns 1t, 2t at the right side of the dryer web form seam loops and are return-plugged into abutment with the warp yarn 3b, the warp yarn 4t abutted against the weft yarn 1w is return-plugged into abutment with the warp yarns 5b, 6b. All the return-plugged warp yarns must be bent and return-plugged according to the dryer web texture structure by the warp yarns formed during the processing, the seam area of the return-plugged parts is consistent with the texture structure of the dryer web except the butted breakpoints. As the upper and lower structures are independent of each other, the upper and lower warp yarns will never intersect with each other, and the plugging connector will always remain on the machine surface without penetrating the web body to the sticker surface and damaging the page sheets.

(28) FIG. 7 is a cross-sectional view along the line C-C of the dryer web seam of FIG. 6. The seam loops at the left and right sides come into meshing abutment with each other and then are connected by one or more threading-yarns (the PIN in the figure), such that the dryer web forms a closed loop. At the same time, filling the seam loops with two filling-yarns 1p of suitable size, which can effectively reduce the gap in the seam area and avoid the occurrence of paper prints while ensuring the convenience of accessing to the web. Since the flexibility of this kind of textured structure, the seam is not limited to the types shown in FIG. 6 and FIG. 7, and two narrow warp yarns can be selected from the left side as the seam loop and two narrow warp yarns can also be selected from the right side as the seam loop; or one wide warp yarn can be selected from left side as the seam loop, and one wide warp yarn can be selected from right side as the seam loop. When the left and right sides are using narrow yarns as the seam loops, it can also make spiral loop seam.

Embodiment 2

(29) The double-layer structure is that: one sub-unit of upper warp yarns has two parallel narrow warp yarns and the other sub-unit also has two parallel narrow warp yarns; one sub-unit of lower warp yarns has two parallel narrow warp yarns and the other sub-unit also has two parallel narrow warp yarns; two parallel narrow warp yarns of the upper sub-unit and two parallel narrow warp yarns of the lower sub-unit are vertically overlapped.

(30) That is, one sub-unit of upper warp yarns is two parallel warp yarns 11t, 12t with a rectangular cross-section, the other sub-unit is two parallel narrow warp yarns 13t and 14t with a rectangular cross-section; one sub-unit of lower warp yarns is two parallel narrow warp yarns 15b, 16b with a rectangular cross-section, the other sub-unit is two parallel narrow warp yarns 17b, 18b with a rectangular cross-section. The warp yarns in the 4 sub-units are woven in accordance with the texture diagram in Table 1 to form dryer web fabrics and are alternately arranged in the entire web.

(31) FIG. 8 and FIG. 9 are 3D views of the front and back of the dryer web fabrics in Table 2. As shown in the 3D views, the widths of the warp yarns in the upper warp yarn sub-unit are substantially equal to the widths of the warp yarns in the lower warp yarn sub-unit, and the warp yarn widths in different warp yarn sub-units in each layer are also substantially the same. For example, the cross-sectional dimensions of 11t, 12t are 0.36 mm0.53 mm, the cross-sectional dimensions of 13t or 14t are 0.36 mm0.53 mm, the cross-sectional dimensions of 15b or 16b is 0.36 mm0.53 mm, and the cross-sectional dimensions of 17b and 18b are 0.36 mm0.53 mm.

(32) It can also be seen from FIG. 8 and FIG. 9 that the front texture of the dryer web is exactly the same as the back texture of the dryer web. Compared with the traditional design with different back and front textures, the present application can effectively eliminate the stress difference caused by the difference of the front and back textures, improve the consistency of the web texture remarkably, and obtain the smoother and flatter surface of the web. The backs of the warp yarns 11t, 12t, 13t and 14t in the white frame of FIG. 8 are the warp yarns 15b, 16b, 17b and 18b in the white frame of FIG. 9; similarly, the weft yarns 2w and 4w can also be seen accordingly.

(33) FIG. 10 is a cross-sectional view along the line D-D of the dryer web in FIG. 8. This 3D view shows only the texture structure of warp yarns 11t, 12t, 15b, 16b and weft yarns 11w, 12w, 13w, 14w. It can be clearly seen from the figure that the diameters of 11w and 13w are thicker and the diameters of 12w and 14w are smaller. The upper warp yarn sub-units 11t and 12t are oriented in three upward and one downward, that is, three of them are above the weft yarns 11w, 12w and 13w and the other is below the weft yarn 14w. The lower warp yarn sub-units 15b and 16b are oriented in one downward, one upward and two downward, that is, one of them is below the weft yarn 11w, one of them is above the weft yarn 12w and the other two are below the weft yarns 13w, 14w. The aforementioned warp and weft yarns cycle back and forth to form a first group of warp and weft yarn texture structure.

(34) TABLE-US-00002 TABLE 2 Texture diagram of the second embodiment 11t 12t 15b 16b 13t 14t 17b 18b 14w x x x x 13w x x x x 12w x x x x 11w x x x x Weft Yarns Yarn Diameter 14w Diameter : 0.40-0.70 mm 13w Diameter : 0.70-1.00 mm 12w Diameter : 0.40-0.70 mm 11w Diameter : 0.70-1.00 mm Warp Yarns 11t 12t 15b 16b 13t 14t 17b 18b Upper layer Lower layer Upper layer Lower layer Yarn Thickness Thickness Thickness Thickness Diameter (mm): (mm): (mm): (mm): 0.25-0.50 0.25-0.50 0.25-0.50 0.25-0.50 Width (mm): Width (mm): Width (mm): Width (mm): 0.40-0.80 0.40-0.80 0.40-0.80 0.40-0.80

(35) FIG. 11 is a cross-sectional view along the line E-E of the dryer web in FIG. 8. This 3D view shows only the texture structure between warp yarns 13t, 14t, 17b, 18b and weft yarns 11w, 12w, 13w, 14w. Similarly, it can be seen from the figure that the diameters of 11w, 13w are thicker and the diameters of 12w and 14w are smaller. The upper warp yarn sub-units 13t and 14t are oriented in one upward, one downward and two upward, that is, one of them is above the weft yarn 11w, one of them is below the weft yarn 12w and the other two are above the weft yarns 13w, 14w; the lower warp yarn sub-units 17b, 18b are oriented in three downward and one upward, that is, three of them are below the weft yarns 11w, 12w, 13w and the other is above the weft yarn 14w. The aforementioned warp and weft yarns cycle back to form a second kind of warp and weft texture structure and form a complete weave texture together with the first group of texture structure, which penetrates all the web bodies of the dryer web.

(36) FIG. 12 shows the 3D front view of the dryer web seam. As shown in the figure, when the warp yarns 12t, 14t on the left side are return-plugged, leaving a sufficient length of warp yarns as seam loops for return-plugging and forming the seam loops (i.e. 12t-loops and 14t-loops) at the left side of the dryer web end; similarly, when the warp yarns 11t, 13t on the right side are return-plugged together, leaving a sufficient length of warp yarns for return-plugging and forming return-loops (i.e. 11t-loops and 13t-loops) at the right side of the dryer web end. When warp yarns 11t, 13t are return-plugged at the left side of the dryer web, they are return-plugged in tight against the weft yarn 11w and form return-loops (i.e. 11t-return and 13t-return) and leave empty spaces for the seam loops of the warp yarns 11t and 13t at the right side of the dryer web; when the warp yarns 12t and 14t at the right side is return-plugged and in tight against the weft yarn 13w to form return-loops (i.e. 12t-return and 14t-return), and leave empty spaces for the seam loops formed by the warp yarns 12t and 14t at the left side. The seams are into abutment with each other by the seam loops formed on the left and right sides and the space formed adjacent to the weft yarns, and the web body is connected into a loop by threading the seam loops.

(37) FIG. 13 is a 3D rear view of the dryer web seam. As shown in the figure, the warp yarns 11t and 13t at the left side of the dryer web, which are abutted against the weft yarn 11w and into abutment with the warp yarns 15b, 17b, the warp yarns 12t, 14t form seam loops and come into abutment with the back warp yarns 16b and 18b; the warp yarns 12t and 14t at the right side of the dryer web, which are abutted against the weft yarn 13w and into abutment with the back warp yarns 16b, 18b, the warp yarns 11t, 13t form seam loops and come into abutment with the back warp yarns 15b, 17b. All the return-plugged warp yarns must be bent and return-plugged according to the dryer web texture structure by the warp yarns formed during the processing, the seam area of the return-plugged parts is consistent with the texture structure of the dryer web except the butted breakpoints. As the upper and lower structures are independent of each other, the upper and lower warp yarns will never intersect with each other, and the plugging connector will always remain on the machine surface without penetrating the web body to the sticker surface and damaging the page sheets.

(38) FIG. 14 is a cross-sectional view along the line F-F of the dryer web seam of FIG. 7. The seam loops at the left and right sides come into meshing abutment with each other and then are connected by one or more threading-yarns (the PIN in the figure), such that the dryer web forms a closed loop. Since the complete consistency of the texture structure, either one of the upper and lower layers can be used as a seam loop, and either one of two parallel warp yarns can also be used as a seam loop. Since the widths of two parallel warp yarns are smaller, compared with the seam loops made by conventional wide yarns, the resulting seam gap is half as narrow as the gap formed by the wide warp yarns of two-width. At the same time, filling the seam loops with two filling-yarns 11p of suitable size, which can effectively reduce the gap in the seam area and avoid the occurrence of paper prints while ensuring the convenience of accessing to the web.

Embodiment 3

(39) In the third embodiment of the present application, one sub-unit of upper warp yarns is a wide warp yarn with a rectangular cross-section, the other sub-unit is two parallel narrow warp yarns with a rectangular cross-section; one sub-unit of lower warp yarns is two parallel narrow warp yarns with a rectangular cross-section, the other sub-unit is a wide warp yarn with a rectangular cross-section. Wherein one wide warp yarn on the upper layer and one wide warp yarn on the lower layer are vertically overlapped, and the widths of the upper wide warp yarns and lower wide warp yarns are basically the same.

Embodiment 4

(40) the double-layer structure is that the cross-section of the web has the following arrangement sequence: upper warp yarns in warp yarn sub-units have two wide warp yarns and four narrow warp yarns, the corresponding lower warp yarns have four narrow warp yarns and two wide warp yarns (not shown)

Embodiment 5

(41) the double-layer structure is that the cross-section of the web has the following arrangement sequence: upper warp yarns in warp yarn sub-units have three wide warp yarns and six narrow warp yarns, the corresponding lower warp yarns have six narrow warp yarns and three wide warp yarns (not shown).